Dry A Highlander by Rebecca Preston

When Delphine travels the Isle of Skye and accidentally finds herself thrown back in time to ancient Scotland, she catches the interest of attractive Eamon MacLeod but is also at center of a mysterious plague and accusations of witchcraft…
Occult bookstore owner and practicing witch Delphine Owens arrives on her free vacation to the Isle of Skye embracing the time away from the ultra-conservative protestors harassing her store. Initially shocked and unprepared for her transport back in time, she’s pleasantly surprised to catch the attention of an attractive Scotsman. But when a witch is blamed for a mysterious illness, Delphine gets nervous.
Serious, workaholic loner Eamon MacLeod understands the magic the Keep is steeped in, so he isn’t surprised by Delphine’s appearance from the future, until the village is hit with a sudden illness the very next day. After training as a witch hunter for the church during years away from the castle due to his father’s exile, Eamon investigates the claims the plague may be caused by the very thing he’s uniquely qualified to track down.
When the investigation points to the work of a witch, Cara must trust the man she barely knows but already cares for with who and what she really is in order to find the truth, or else, she might end up burning at the stake.